---
title: Semantic Tokens
description:
  Chakra UI provides built-in support for conditional semantic design tokens
category: 'features'
---

Chakra UI supports **conditional semantic tokens** for every scale (colors, font
sizes, etc). This allows to change the value of a token depending on the
environment, like dark mode, direction and other CSS selectors.

We are using CSS variables which can change with a CSS condition. E.g. the color
token `text` can have a different value in dark and light mode.

## Token References

A semantic token value can be a `string | SemanticValue`. The `string` value is
used as reference to another token in the same scale e.g.

```js
{
  error: 'red.500'
}
```

## Conditional Tokens

The object notation `SemanticValue` allows to define the default value and
conditional keys. The condition can be one of
[chakra pseudo selectors](/docs/styled-system/style-props#pseudo) or a
custom CSS selector. Try `_dark`, `_light`, `_rtl`, `_ltr` and
`_mediaReduceMotion`.

If you are tempted to use a CSS selector like `_focus`, `_hover` etc. define
those CSS variables at the component level.

The CSS variables are attached to the host element (CSS selector `:host, :root`)
and cannot react to the components `<LightMode />` and `<DarkMode />`,
`data-theme` attributes nor body class `.chakra-ui-dark`. It listens to e.g.
`html[data-theme="dark"]`.

> Since the CSS variables are attached to the host element by default we can
> only specify certain CSS selectors. E.g. `_hover` would always trigger, when
> the `html` element is hovered - that's mostly not intended.

```js
{
  text: {
    default: 'gray.900',
    _dark: 'gray.50'
  }
}
```

Semantic Tokens can reference theme tokens like `gray.900` and allow plain CSS
values like e.g. `#F7FAFC`.

```jsx live=false
import { ChakraProvider, extendTheme } from '@chakra-ui/react'
const customTheme = extendTheme({
  semanticTokens: {
    colors: {
      error: 'red.500',
      text: {
        default: 'gray.900',
        _dark: 'gray.50',
      },
    },
  },
})

const App = () => (
  <ChakraProvider theme={customTheme}>
    <Text color='text'>
      will be gray.900 in light mode and gray.50 in dark mode
    </Text>
  </ChakraProvider>
)
```

## Theme Example

```jsx live=false
import { extendTheme } from '@chakra-ui/react'

const theme = extendTheme({
  semanticTokens: {
    colors: {
      error: 'red.500',
      success: 'green.500',
      primary: {
        default: 'red.500',
        _dark: 'red.400',
      },
      secondary: {
        default: 'red.800',
        _dark: 'red.700',
      },
    },
  },
})
```
